My heart goes out to your niece. My daughter is 16 y.o. at the moment. I tell her I DO NOT want her to marry until she has:
1) gone to college
2) have a REAL career (as MANY J-dubbs do not have)
3) travel, have fun, have a FEW boyfriends to find out what YOU wannt and what YOU like
4) live on your own by the morals I have taught you.................... BUTTTT!!!!!!!!!!!!!!!!!!!
5) do not subject yourself to ANY religious organizations until you have lived YOUR OWN LIFE. This would help you to figure out if this religion IS what YOU WANT.
As J-dubbs....YOU have absolutely NO CHOICES in life.
Please encourage your niece to live HER life. Jehovah gave it to her at "free-will".